Fire place conversion unit



Dec. 9, 1958- J. HoFFMAN FIRE PLACE CONVERSION UNIT 2 Sheets-Sheet 1.

Filed July 8. 1955 l l 1 I I l Illl l l l l l l I I INVENTOR.

HOFFMAN Jol-AN Dec. 9, 1958 J. HOFFMAN FIRE PLACE: CONVERSION UNIT 2 Sheets-Sheet 2 Filed July s. 1955 INVENTOR.

HC \=l= M AN FIRE PLACE CONVERSION UNIT John Hoffman, Ocean Grove, N. J.

Application July 8, 1955, Serial No. 520,757

3 Claims. (Cl. 126-121) This invention relates to a heating apparatus for installation in existing, open hearth fireplaces.

It is well known that open fireplaces are highly inefficient in use, and accordingly, it has heretofore been proposed to install, `in a fireplace of this type, means for converting the fireplace into a space heater. Ordinarily, the installation of units of this type involves considerable expense, whether said installation be effected at a time following completion of the fireplace or, alternatively, during actual construction of the fireplace. In some instances, the units must in fact be installed at the time the fireplace is being constructed, and in the remaining instances, the installation is attended with considerable difficulty, and entails a considerable expense requiring extensve modification `or preparation of the fireplace,`

acco-mplished only by the use of skilled labor.

The main object of the present invention is to provide a generally improved heating unit for fireplaces, so designed as to particularly facilitate its partial preassembly or fabrication, with installation of the unit being capable of being accomplished by the householder himself, with an attendant reduction in costbelow that normally required for installation of a unit of this type.

Another object of importance is to provide a unit as stated which will be so designed as to provide for greater heating efficiency than many similar units already in use.

Still another object of importance is to provide a fireplace conversion unit which will be so designed as to permit the same to be readily adapted for installation in fireplaces of various shapes and sizes.

Yet another object is to form the fireplace unit in such a manner as to provide an attractive installation which will detract to a minimum from the exterior appearance of the fireplace.

Other objects will appear from the following description, the claims appended thereto, and from the annexed drawings in which like reference characters designate like parts throughout the several views and wherein:

Figure l is a front elevational view of a fireplace in which has been installed a conversion unit formed accordingzto the present invention;

Figure 2 is a vertical section on line 2 2 of Figure l;

Figure 3 is a horizontal section on line 3--3 of Figure l;

Figure 4 is a vertical sectional view at right angles to the cutting planeof Figure 2, taken on line 4 4 of Figure 2;

Figure 5 is an exploded perspective View, portions being broken away, of the conversion unit per se.

A conventional fireplacegenerally designated includes the usual combustion chamber or fire pit 12, and the flue 14 extending upwardly from and communicating with the upper end of said combustion chamber.

The device constituting the present invention has been generally designated" at 16, and includes a rectangular fire box adapted to fit into the combustion chamber of i116? fireplace. The re'box is, as shown in Figure 5,

- United States Patent 0 f Vof the fireplace.

Patented Dec. 9, 1958 fice made in two sections, these being a lower section generally designated 17, and an upper sectiongenerally designated at 19. Each of these sections may be preassembled during manufacture of the device, and then connected to one another within the fireplace, in a manner to be made presently apparent.

The lower section 17 of the fire box includes a hori zontal bottom wall 18, and (see Figure 2) projecting upwardly from the rear edge of the bott-om wall 18 is a low back wall section 2l. Low, upstanding side walls 22 are provided upon the opposite side edges of the bottom wall f8, and these are connectable, within the fireplace, to the botto-m edges of the upper side wall portions 23, provided on the upper re box section 19. The upper fire box section additionally includes a back wall 20, interfitting, in the same manner as the side wall portions 22, 23, with the back wall 21 of the lower fireplace section. The back and side walls of the lower fireplace section, as shown in Figure 2, can have upwardly projecting, inwardly offset flanges defining shoulders against which the lower edges of the back and side walls rof the upper fireplace section abut, after which screws or equivalent fastening elements can be employed to complete the construction of the rectangular, open front fire box illustrated in Figure 5.

Connectable by bolts or equivalent fastening elements to the side edges of the fire box, are vertically disposed flanges 24, the lower ends of which extend below the botto-m wall 18 to provide supporting legs for the fire box at the front thereof. Provided upon the rear corners of the lower section 17 are rear legs 26, cooperating with the front legs to. support the bottom wall 18 in a plane elevated above the bottom of the fireplace.

A top wall 28 is provided upon the fire box, said top wall being open at its rear and being in communication at this point with an upwardly tapering extension charnber 30 in which the hot products of combustion are collected, said chamber being formed integrally with the top wall in the illustrated example of the invention, but being adapted to be preformed as a separate unit if desired.

Secured to and projecting inwardly from the several walls of the chamber 30 (see Figure 2) are brackets 32 disposed in a common horizontal plane, and supported upon said brackets is a horizontally positioned baffle 34, the edges of which are spaced inwardly from the side walls of the collection chamber.

Above the baffle 34, the collection chamber 30 is formed with a low, upstanding neck 36, in which is fitted the lower end of a cylindrical stack 3S, the upper end portion of which extends through an opening 40 formed in an inclined partition or shelf 42 the edges of which abut snugly against the side walls of the fiue 14. The rear edge of the partition is supported upon the inwardly projected upper end portion of an elongated support bar 44 secured at its lower end to the rear of the fire box.

Immediately below the forward edge of the partition 42 there is formed an inclined opening 46,. said opening being formed in the front wall of the filue and communicating between the room space and the area within the flue disposed below the partition 42, to provide an outlet for heated air into the room space. A screen 5t) or other type of grille is mounted across the outlet of the opening 46.

Within the lower portion of the fire box, a grate 52 is suported upon brackets 54, and below the grate, there is` centrally formed in the bottom wall 13 an opening, communicating with the upper end of a depending pipe 56, mounted in a center opening 58 formed in the bottom A door 60 is hinged to the lower end 3 of the pipe 56, and is normally engaged in a closed position by a hasp and pin means or similar device.

Extending laterally from the lower portion of the pipe 56 in communication therewith is an air inlet pipe 62, the inlet end of which will be incommu'nication with atmosphere at a location outside the house.

In the upper portion of pipe 56 thereY is mounted' a darn er 64, from which extends a 'controlrodt66 projecting through a vertically disposed frame plat-e -68'extending transversely of the fireplace and connectable'atits ends to the anges 24. The frame plate Y68 has an elongated, slot-like opening, in which'is mounted a Vslidable closure 7d, the handle 72 of the damper control rod 66 projecting through said 'closure to vpermit operation of the damper from within the room, regardless of the position of the closure 70. The closure has a longitudinal series of vertically disposed inlet openings, said openings being fully opened in one positionfof the closure and being closed or only partially opened in other positions of said closure'to control the passage of air therethrough into the fire chamber of the fireplace, about the fire box.

A pair'of doors 74, formed to include door frames in which are 4mounted panes of fire resistant, tempered glass, are provided with hinges at theirouter side edges connectabletoithe frame plate 63.

ln installing the unit, an air vent opening 46 is cut in the vfront wall of the chimney at the desired height, after which the `partition or shelf 42 is installed in an inclined position in the chimney just above the air vent opening, -so asto direct warm 'air into the room. The metalstack 38 is then inserted in the chimney through the partition and is secured in place.

The upper section 19 of the iire box is now inserted through the fireplace opening and installed, with the stack being fitted tothe neck 36. Then, the lower section of the fire'box, designated at 17, is placed under the upper section and secured thereto. The side flanges 24 are now installed, to'close the air spaces at the sides of the fire box -wi'thin 'the ifireplace opening, after which the doors and the frame plate 655 are attached to said side lianges. The combination ash disposal and outside air inlet conduit 56, 62 may now be installed, should such conduit be desired.

It will be seen that the device can be partially preassembled, so as to constitute a prefabricated unit capable of installation in an existing fireplace with minimum difficulty and expense.. j

In use of the unit, draft air enters the fire box through the conduitf62, 56, with the inflow of air being regulated by the damper 64. The vdoors are, of course, kept closed, and the air will pass upwardly within the lire box through the grate, to maintain combustion of fuel supported on the grate. The hot products of combustion pass'upwardly through the stack 38 and out the existing chimney. Meanwhile, air is drawn into the space surrounding the tire box at the sides, bottom, and back thereof, from the room, through the openings of the closure 70, in the direction ofthe arrows shown in Figure 2. The walls of the tire box Vare of a sheet metalhaving a high rate of thermal conductivity and radiation, .and hence the air passing about the fire box is warmed, Vmoving upwardly as a consequence within the space surrounding the stack 38 below partition 42, and passing through the air outlet conduit 48 into the room space.

In the thus described invention, there is the desirable characteristic wherein the device can be formed in preassembled components, with said components being readily connectible directly within the fireplace in minimum time and without the requirement of skilled labor. The unit, once installed7 provides a space heater for the room, with the room air being'continuously recirculated through the space surrounding the tire box and stack below the partition, for continuous warming of the air. Further, additional `heat is radiated .through the glass panels of the doors, further adding to the heating ef- 'iciency of the device.

It is believed apparent that the invention isnot necessarily limited to the specific use or uses thereof described above since it may be utilized for any purpose to which it may be suited. Nor is the invention to be necessarily limited to the specific construction illustrated and described, since such constructionis only intended to be illustrative of the principles it being considered that the invention comprehends any minor change inconstruction that may be permitted within the -scope 'of the appended claims.

What is claimed is:

l. A heating unit comprising a firebox adapted to be installed in a space having a communicating flue, said box including a lower section embodying a horizontal bottom wall having a rear edge, 'a pair of side edges and a front edge, a back wall extending along the rear edge of l.said bottom lwall and a side wall extending along each of the side edges of said bottom wall, each of said back and sidewalls being provided with a shoulder extending therealong adjacent `-the upper end thereof, an upper isection embodying a top wall having a rear edge, a 'pair-of-s-ide edges and a front' edge, aback'wall extendingalong'tne rear edge of said top wall and a sidewall extending alongeach of the sideedges of said top wall, said `upper section being positioned so that the lower ends of `Said back and side -walls thereof abut and rest vupon the shoulders -of theiback and side walls of said lower section with the top wall in spaced parallel relationwith respect to the bottom wall'of said lower section, means vdetachably securing the `portions of the back and sidewalls of said upper section adjacent the lower ends of the adjacent portions of the Vback and side walls of said lower section, a vertically disposed frame ,plate extending'between and abutting the front edges of the wall of said lower section and the top wall of said upper sectionand detachably secured to the adjacent edges of the side walls of said lower and upper sections, there being a closed'sl'ot in said frame plate, aclosure slidably mounted on said plate and movable'over said slot, a chamber rising from the top wall of said upper section, a neck in said chamber, and a shelf positioned above and spaced from said neck and adapted to be arranged in an inclined direction in a communicating ue of a space in which saidiirebox is installed.

2. A heating unit comprising a ir-ebox adapted to be installed in a space having a 'communicating flue, said box including a lower section embodying a horizontal bottom Awall having a rear edge,l a pair of side edges and a front edge, a back wall extending along the rear edge' of said bottom wall and a side wall extending along each of the side edges of said bottom wall, each of said back and side walls being provided with a shoulder extending therealong adjacent the upper edge thereof, and an upper 'section embodying a to'p wall lhaving a rearedge, a pair of side edges and `a front edge, aback wall extending along the rear edges of said top wall, and a side wall extending along "each of `thefside edges of said top wall, -said 'upper se'ction'being positioned so that the lower edges of said back and side walls thereof abut and rest upon the shoulders of the back and side walls of said lower section with lthe top wall in parallel spaced relation with respect to the bottom wall of s'aid lower section, means detachably securing the portions of the back and side walls of said upper section adjacent the l lower edges to the adjacent portionsof the back 'and side walls oflsaid .lower section, a vertically disposed frame plate extending between and abutting the front edges of the bottom wall of said lower `section and the ltop wall of said upper'section and detachably secured to the adjacent edges lof the side walls of said lower and upper sections, there being a closed slot in said frame plate, a closure 'slidably mounted onsaid frame plate and movable ov'ertsa'id slot, a chamber rising from the top-wall of said upper section, a neck on said chamber, a shelf positioned above and spaced from said neck and adapted to be arranged in an inclined direction in a communicating flue of a space in which said rebox is installed, and a stack adapted to be arranged in the communicating ue of a space in which said rebox is installed and having the lower end received and supported in said neck and extending through said shelf.

3. A heating unit comprising a rebox adapted to be installed in a space having a communicating flue, said box including a lower section embodying a horizontal bottom wall having a rear edge, a pair of side edges and a front edge, a back wall extending along the rear edge of said bottom wall and a side wall extending along each of the side edges of said bottom wall, each of said `back and side walls being provided with a shoulder extending therealong adjacent the upper edge thereof, and an upper section embodying a top wall having a rear edge, a pair of side edges and a front edge, a back Wall extending along the rear edge of said top wall and a side wall extending along each of the side edges of said top Wall, said upper section being positioned so that the lower edges of said back and side walls thereof abut and rest upon the shoulders of the back and side walls of said lower section with the top wall in parallel spaced relation with respect to the bottom wall of said lower section, means detachably securing the portions of the back and side walls of said upper section adjacent the lower edges to the adjacent portions of the back and side Walls of said lower section, a vertically disposed frame plate extending between and abutting the front edges of the bottom wall of `said lower section and the top wall of said upper sections and detachably secured to the adjacent edges of the side walls of said lower and upper sections, there being a closed slot in said frame plate, a closure slidably mounted on said frame plate and movable over said slot, a chamber rising from the top wall of said upper section, a neck on said chamber, and a horizontally disposed bale xedly positioned within said chamber and spaced below said neck.

References Cited in the le of this patent UNITED STATES PATENTS 660,357 Barber Oct. 23, 1900 737,382 Frederick Aug. 25, 1903 817,900 Brandes Apr. 17, 1906 1,588,587 Klaus June 15, 1926 1,620,235 Royse Mar. 8, 1927 1,649,881 Williamson Nov. 22, 1927 1,681,995 Miles Aug. 28, 1928 2,093,492 Snyder Sept. 21, 1937 2,453,954 Wright Nov. 16, 1948 2,743,720 Dollinger May 1, 1956 FOREIGN PATENTS 5,594 Great Britain Mar. 28, 1884 18,077 Great Britain of 1909 

